A 3.50 L balloon contains 0.178 mol of gas. If 0.094 mol of gas is

In a hospital laboratory, a 10.0 mL sample of gastric juice (predominantly HCl), obtained several hours after a meal, was titrat

LiRa [457]

Answer: 1.14

Explanation:

$HCl+NaOH\rightarrow NaCl+H_2O$

To calculate the molarity of acid, we use the equation given by neutralization reaction:

$n_1M_1V_1=n_2M_2V_2$

where,

$n_1,M_1\text{ and }V_1$ are the n-factor, molarity and volume of acid which is $HCl$

are the n-factor, molarity and volume of base which is NaOH.

We are given:

$n_1=1\\M_1=?\\V_1=10.0mL\\n_2=1\\M_2=0.1M\\V_2=7.2mL$

Putting values in above equation, we get:

$1\times M_1\times 10.0=1\times 0.1\times 7.2\\\\M_1=0.072M$

To calculate pH of gastric juice:

molarity of $H^+$ = 0.072

$pH=-log[H^+]$

$pH=-log(0.072)=1.14$

Thus the pH of the gastric juice is 1.14

3 0

3 years ago

Substances that are readily combustible or may cause fire through friction

Dvinal [7]

Answer :

Flammable substances

Explanation :

Flammable substances will catch fire and continue to burn when they contact an ignition source like a spark or a flame.

For example, methanol is a flammable liquid.

A flammable solid may also catch fire through friction. Matches are flammable solids.

3 0

3 years ago

Carbon obtained from a sample of frozen skin in a glacier is found to have one-half the 14c-to-12c ratio of present-day carbon.

Otrada [13]

Check the attached file for the answer.

8 0

3 years ago

What mass of CaSO3 must have been present initially to produce 14.5 L of SO2 gas at a temperature of 12.5°C and a pressure of 1.

german

When the reaction equation is:

CaSO3(s) → CaO(s) + SO2(g)

we can see that the molar ratio between CaSO3 & SO2 is 1:1 so, we need to find first the moles SO2.

to get the moles of SO2 we are going to use the ideal gas equation:

PV = nRT

when P is the pressure = 1.1 atm

and V is the volume = 14.5 L

n is the moles' number (which we need to calculate)

R ideal gas constant = 0.0821

and T is the temperature in Kelvin = 12.5 + 273 = 285.5 K

so, by substitution:

1.1 * 14.5 L = n * 0.0821 * 285.5

∴ n = 1.1 * 14.5 / (0.0821*285.5)

= 0.68 moles SO2

∴ moles CaSO3 = 0.68 moles

so we can easily get the mass of CaSO3:

when mass = moles * molar mass

and we know that the molar mass of CaSO3= 40 + 32 + 16 * 3 = 120 g/mol

∴ mass = 0.68 moles* 120 g/mol = 81.6 g

7 0

3 years ago

How can we find the number of moles in equilibrium?

pychu [463]

You can find the number of moles in equilibrium if you got the chemical reaction correctly. Make sure that you got the exact chemical formula of the substance that is reacting and the yielded product. If you got them, balance the chemical reaction. If the chemical reaction is balanced, the system is in equilibrium. You can find the number of moles in equilibrium at the coefficients of the chemical substances you are balancing. For example, N2 + 3H2 -> 2NH3. The number of moles of N2 is 1, H2 is 3 and NH3 is 2.

5 0

3 years ago